The present invention relates to a linear motion anti-friction rolling bearing for longitudinal movements of a shaft or the like. Such a bearing includes an outer sleeve with axial races in its bore for the rolling elements under load and returned paths for the elements not under load, a cage seated in the bore with a plurality of circumferentially distributed channels consisting of axial races for the rolling elements under load and not under load and semicircular turnarounds connecting these races with each other in pairs, and rows of rolling elements arranged in these channels. There are two end rings, each covering one end of the cage radially on the outside, with the inner faces of these rings arranged in close juxtaposition to the corresponding faces of the outer sleeve.
A known bearing of this kind is furnished with lubricant such as grease at the time of assembly and/or before installation. This known bearing cannot be relubricated during operation; however such would be desirable in many cases where the bearing experiences high stresses.
To provide the possibility of additional lubrication, conventionally a radially extending aperture is formed in the wall of the outer sleeve or end ring for the rolling elements in each channel, this aperture opening directly into one of the turnarounds or races. Linear motion anti-friction rolling bearings provided with such radial apertures have the disadvantage that these apertures must be produced by a separate operation, for example by drilling or punching. Furthermore, a radial aperture in the wall of the outer sleeve or end ring must be provided for each individual channel, so that there are a comparatively large number of apertures to be made. For this reason, the known bearing is comparatively expensive to manufacture. Another disadvantage in the known bearing is its vulnerability to the danger that dirt may enter directly into the channels during transport or installation of the bearing, tending to damage or jam the rolling elements.